Question

change in a kind of organism over time and have descended from an ancient organism

Answer 1

What you're describing is known as **evolution**. Evolution is the process through which populations of organisms change over generations, leading to the development of new species from common ancestors. This process is driven by mechanisms such as natural selection, genetic drift, mutations, and gene flow. Over long periods, these changes can result in significant differences between ancestral and descendant organisms, highlighting the diversity of life on Earth. The concept of common descent illustrates that all living organisms share a common ancestor, linking them through a vast tree of life.